def _read_data_page(fo, schema_helper, page_header, column_metadata, dictionary):
daph = page_header.data_page_header
raw_bytes = _read_page(fo, page_header, column_metadata)
io_obj = cStringIO.StringIO(raw_bytes)
vals = []
column_path_name = ".".join(column_metadata.path_in_schema)
logger.debug(" path_in_schema: %s", column_path_name)
logger.debug(" definition_level_encoding: %s", _get_name(Encoding, daph.definition_level_encoding))
logger.debug(" repetition_level_encoding: %s", _get_name(Encoding, daph.repetition_level_encoding))
logger.debug(" encoding: %s", _get_name(Encoding, daph.encoding))
max_repetition_level = schema_helper.max_repetition_level(column_path_name)
logger.debug(" max_repetition_level: %s", max_repetition_level)
repetition_levels = []
if max_repetition_level > 0:
bit_width = encoding.width_from_max_int(max_repetition_level)
if bit_width == 0:
repetition_levels = [0] * daph.num_values
else:
repetition_levels = _read_data(io_obj, daph.repetition_level_encoding, daph.num_values, bit_width)
logger.debug(" Repetition levels: %s ...", repetition_levels[0:10])
definition_levels = []
max_definition_level = schema_helper.max_definition_level(column_path_name)
logger.debug(" max_definition_level: %s", max_definition_level)
if max_definition_level > 0:
bit_width = encoding.width_from_max_int(max_definition_level)
logger.debug(
" max def level: %s bit_width: %s values: %s", max_definition_level, bit_width, daph.num_values
)
definition_levels = _read_data(io_obj, daph.definition_level_encoding, daph.num_values, bit_width)
logger.debug(" Definition levels: %s ...", definition_levels[0:10])
num_nulls = 0
for i in range(daph.num_values):
if len(definition_levels) > 0:
dl = definition_levels[i]
if dl < max_definition_level:
num_nulls += 1
num_not_null = daph.num_values - num_nulls
if daph.encoding == Encoding.PLAIN:
for i in range(num_not_null):
vals.append(encoding.read_plain(io_obj, column_metadata.type, None))
elif daph.encoding == Encoding.PLAIN_DICTIONARY:
# bit_width is stored as single byte.
bit_width = struct.unpack("<B", io_obj.read(1))[0]
logger.debug("bit_width: %d", bit_width)
total_seen = 0
dict_values_bytes = io_obj.read()
dict_values_io_obj = cStringIO.StringIO(dict_values_bytes)
while total_seen < num_not_null:
values = encoding.read_rle_bit_packed_hybrid(dict_values_io_obj, bit_width, len(dict_values_bytes))
if len(values) + total_seen > daph.num_values:
values = values[0 : daph.num_values - total_seen]
vals += [dictionary[v] for v in values]
total_seen += len(values)
elif daph.encoding == Encoding.DELTA_BYTE_ARRAY:
vals = encoding.read_delta_byte_array(io_obj)
elif daph.encoding == Encoding.DELTA_BINARY_PACKED:
vals = encoding.read_delta_binary_packed(io_obj)
else:
raise ParquetFormatException("Unsupported encoding: %s", _get_name(Encoding, daph.encoding))
return (repetition_levels, definition_levels, vals)
def read_data_page(fo, schema_helper, page_header, column_metadata, dictionary):
"""Reads the datapage from the given file-like object based upon the
metadata in the schema_helper, page_header, column_metadata, and
(optional) dictionary. Returns a list of values.
"""
daph = page_header.data_page_header
raw_bytes = _read_page(fo, page_header, column_metadata)
io_obj = cStringIO.StringIO(raw_bytes)
vals = []
logger.debug(" path_in_schema: %s", ".".join(column_metadata.path_in_schema))
logger.debug(" definition_level_encoding: %s", _get_name(Encoding, daph.definition_level_encoding))
logger.debug(" repetition_level_encoding: %s", _get_name(Encoding, daph.repetition_level_encoding))
logger.debug(" encoding: %s", _get_name(Encoding, daph.encoding))
max_repetition_level = schema_helper.max_repetition_level(column_metadata.path_in_schema)
logger.debug(" max_repetition_level: %s", max_repetition_level)
if max_repetition_level > 0:
bit_width = encoding.width_from_max_int(max_repetition_level)
if bit_width == 0:
repetition_levels = [0] * daph.num_values
else:
repetition_levels = _read_data(io_obj, daph.repetition_level_encoding, daph.num_values, bit_width)
logger.debug(" Repetition levels: %s", repetition_levels)
definition_levels = []
max_definition_level = schema_helper.max_definition_level(column_metadata.path_in_schema)
logger.debug(" max_definition_level: %s", max_definition_level)
if max_definition_level > 0:
bit_width = encoding.width_from_max_int(max_definition_level)
logger.debug(
" max def level: %s bit_width: %s values: %s", max_definition_level, bit_width, daph.num_values
)
definition_levels = _read_data(io_obj, daph.definition_level_encoding, daph.num_values, bit_width)
logger.debug(" Definition levels: %s", definition_levels)
num_nulls = 0
for i in range(daph.num_values):
if len(definition_levels) > 0:
dl = definition_levels[i]
if dl < max_definition_level:
num_nulls += 1
num_not_null = daph.num_values - num_nulls
if daph.encoding == Encoding.PLAIN:
for i in range(num_not_null):
vals.append(encoding.read_plain(io_obj, column_metadata.type, None))
elif daph.encoding == Encoding.PLAIN_DICTIONARY:
# bit_width is stored as single byte.
bit_width = struct.unpack("<B", io_obj.read(1))[0]
logger.debug("bit_width: %d", bit_width)
total_seen = 0
dict_values_bytes = io_obj.read()
dict_values_io_obj = cStringIO.StringIO(dict_values_bytes)
# TODO jcrobak -- not sure that this loop is needed?
while total_seen < num_not_null:
values = encoding.read_rle_bit_packed_hybrid(dict_values_io_obj, bit_width, len(dict_values_bytes))
if len(values) + total_seen > daph.num_values:
values = values[0 : daph.num_values - total_seen]
vals += [dictionary[v] for v in values]
total_seen += len(values)
elif daph.encoding == Encoding.DELTA_BYTE_ARRAY:
vals = encoding.read_delta_byte_array(io_obj)
elif daph.encoding == Encoding.DELTA_BINARY_PACKED:
vals = encoding.read_delta_binary_packed(io_obj)
else:
raise ParquetFormatException("Unsupported encoding: %s", _get_name(Encoding, daph.encoding))
if len(definition_levels) > 0:
null_mixed = []
idx2 = 0
for i in range(daph.num_values):
dl = definition_levels[i]
if dl < max_definition_level:
null_mixed.append(None)
else:
null_mixed.append(vals[idx2])
idx2 += 1
return null_mixed
else:
return vals